Rotating vane machine couplings



March 18, 1969 H. P. BIRKEMEIER v 3,433,166

ROTATING VANE MACHINE COUPLINGS Filed Sept. 11, 1967 [/6. 3 I I 39 L? a5 INVENTOR x/fldm/zx United States Patent 3,433,166 ROTATING VANEMACHINE COUPLINGS Henry Paul Birkemeier, Chicago, 111., assignor toInternational Telephone and Telegraph Corporation Filed Sept. 11, 1967,Ser. No. 666,900 US. 'Cl. 103-118 4 Claims Int. Cl. F04c /00; F04b 21/00ABSTRACT OF THE DISCLOSURE Structure for mounting a rotary vane typemachine utilizing a free floating rotor on a prime mover.

This invention relates generally to rotating vane machines and hasparticular reference to the means used to couple the rotating machine tothe prime mover. More particularly, the invention is an improvement overrotating machines detachably mounted on prime movers such as thatdescribed in US. Patent No. 3,282,222 which issued on Nov. 1, 1966 andis assigned to the assignee of this invention One of the problemsattendant upon the mounting of a driven rotating vane machine such as avane-type compressor upon a prime mover such as an electric motor isthat of coupling the rotor of the driven machine to the prime movershaft. Generally, rotors are press fitted 0n the drive shaft andmetallic keys requiring close tolerances are used to assure instantrotation of the rotor with the rotation of the prime mover shaft. Thistype of coupling introduces inherent concentricity problems. Theproblems are somewhat relieved when the driven machine comprises a freefloating self-centered rotor.

The use of a free floating rotor, however, increases torsional vibrationeffects which tend to accelerate the structural failure of the keys and/or keyways. The means used in the past for lengthening the lift of thekeys and/ or keyways has been to match the keys and keyways to aprecisional tolerance. This, of course, adds to the cost of theequipment and merely delays the ultimate breakdown. When the key orkeyway does shear the driven equipment is usually damaged by the partsof the key and/or keyway which fall onto the moving parts of the drivenequipment.

Additionally, the close tolerance between the metallic keys and keywaysmakes it extremely diflicult if not impossible, to remove the the rotorfor servicing and cleaning without special tools.

Another adverse condition resulting from the use of keys and keywaysfabricated from metal is that the keyways provide fluid leakage pathswhich are not effectively blocked by the metallic keys.

Accordingly, an object of this invention is to overcome the above notedand other adverse effects in coupling the rotary of the driven device tothe drive shaft.

More particularly, it is an object of this invention to provide meansfor overcoming the adversities commonly caused to couplings =bytorsional vibratory effects.

Yet another object of the invention is to provide means for coupling thedrive shaft to the rotor so that noise and vibrations are inherentlyreduced.

Still another object of the invention is to provide coupling meansbetween the rotor and the drive shaft that does not require precisionparts.

A further object of this invention is to provide coupling means thatacts to prevent damage to the moving parts by acting as an overloadrelief.

In accordance with a preferred embodiment of the present invention thereis provided key coupling means comprising keys of dry lubricant, hightemperature material such as Teflon. The keys are used between the motor"Ice shaft of the prime mover and the floating rotor of a vane-typecompressor.

These and other objects and features of this invention and the manner ofobtaining them will become more apparent, and the invention itself willbe best understood by reference to the following description of anembodiment of the invention taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a side elevation view of a prime mover having a rotating vanemachine mounted thereon and driven thereby, said coupling accomplishedusing dry lubricant keys of high temperature material;

FIG. 2 is a transverse section taken along the line 2--2 of FIG. 1looking in the direction of the arrows; and

FIG. 3 is a sectional view taken along lines 3--3 of FIG. 2 looking inthe direction of the arrows.

The rotating vane machine having the improvements according to thepresent invention is shown in the combination of FIGS. 1 and 2 and isdefined generally by the reference numeral 10.

A prime mover 11 having :a base 12 upon which it is supported drives themachine. As shown in FIGS. 1 and 2 the prime mover 11 may be aconventional fractional or integral horsepower motor having an end bell13 which is coterminous with an annular flange extension 14 having abearing therein, not shown, for the support of shaft 16 driven by theprime mover 11.

The rotating vane machine 10 is adapted to be mounted on the annularflange extension 14, and includes a rotor 17 having a. plurality ofslots 18 therein located either on chords or radially with respect tothe center of rotation of the driven shaft 16. The rotor 17 is coupledto the shaft 16 by means of keys 19, '20 engaged in slots 21, 22 on theshaft 16 and in keyway 23, 24 on rotor 17, respectively.

Each of the slots 18 is adapted to receive a vane 25 made of carbon orsimilar material having good selflubricating qualities. Vanes 25 areurged centrifugally into contact with a cylindrical surface 26 of acavity 27 best seen in FIG. 2 within a central body member 28, thecenter of the cavity 27 being concentric to the shaft 16, so that uponrotation of the shaft 16 and the rotor 17 in the direction shown by thearrow in FIG. 2, the vanes 25 will move axially in and out of theirrespective slots 18, all the while tips 29 thereof being in contact withthe cylindrical surface 26.

In the embodiment seen with respect to the drawings, the rotating vanemachine 10 is shown as a compressor, and has an intake or suction port30 leading to the cavity 27, the intake port 30 being continuous withadditional port area 31 to give good volumetric efliciency as the vanes25 turn with the rotor 17. The body member 28 also has an outlet port32, and the gas which is compressed between the adjacent vanes 25 byreasons of the decreasing volume swept thereby as the rotor turns in thedirection shown exits from body member 28 through the outlet port 32.

A lapping land 33 between the inlet port 30 and the outlet port 32 is incontact with one of the blades 25 as it reaches the end of itscompressed fluid delivering movement. At other times the surface of therotor 17 is spaced but a very small distance from the surface of theland 33, there being a clearance afforded of the order of .001" to.002". This very small clearance being necessary for the free turning ofthe rotor 17, not yet causing any appreciable losses from thecompression or exhaust side to the intake or suction side.

It should be understood that any clearances described are merelyillustrative, and will vary in accordance with the parameters of thestructure.

The close tolerances accentuate the torsional vibratory effects. If keys19, 20 are metallic, the vibratory effects results in noisy operation.

Means, such as keys 19, 20 fabricated from dry lubricants are providedfor dampening the inherent vibrations and noises. The lubricants usedsuch as filled Teflon are high temperature material.

The Teflon filled keys additionally are self-sizing to form such a tightnon-metallic contact with the keyways that leakage through the keywaysis prevented. Nonetheless, the use of such keys enables the reduction ofprecision requirements for keys and keyways. Thus, it is possible toeasily remove the rotor for servicing and cleaning without the necessityfor using special tools.

The rotor 17 is adapted to turn between carbon thrust faces 34 and 36,these faces being in close contact with the rotor ends to preventleakage around the ends thereof. Thrust faces of materials other thancarbon may be employed, and the nature of the material forming thethrust face is of no particular significance in this invention. Thrustface 34 is held in an inner end member 37 having a bore 35 in the endthereof to enable inner end member to be placed on flange 14 and to besecured thereto in a manner as will be described. Likewise, thrust face36 is held in the outer end member 38, the two members 37 and 38 beingheld together with the body member 27 therebetween by means of long capscrews 39 threaded at 41 to the end member 37 and having heads 40bearing against outer end member 38.

In forming the thrust faces 34 and 36 in the respective end members 37and 38, in each case they are placed in a recess 42, and the wearingsurface of the thrust faces 34 and 36 are made coextensive and coplanarwith the members 37 and 38, as for example, in a surface grinding operation.

The inner end member 37 is drilled and tapped radially to receive ateach such drilled and tapped point a set screw 44 having a conical end46 adapted to be received in an annular V-groove 47 formed on the endannular flange 14. When the end member 37 is thus placed on flange 14,and properly located radially thereon, the rotor 17 is then secured toshaft 16 by the keys 19, 20. In so doing the rotor 17 is brought againstthe carbon wear element 34 mounted in end member 37.

Any portions of the filled keys that may be separated from the keysduring assembly, act to lubricate the contiguous parts of the assembly.This is in contrast to the portion of the metallic keys that may fallinto the moving assembly.

Body member 38 is next located on the end member so as to afford aproper running clearance between the rotor 17 and the land 33 of bodymember 28 and between the inlet port 30 and outlet port 32. This is doneby inserting a feeler of .001" to .002" thickness between rotor 17 andland 33, and at a point along the surface of rotor 17 between adjacentvanes 25.

The aforesaid position of rotor 17 with respect to land 33 is maintainedby pilot screws 48, see FIG. 3, having heads 50 which are countersunk at49 in the body member 27 and tapped at 51 into inner end members 37.Each of the pilot screws 48 extends through a bore 52 in body member 28,pilot screw 48 fitting somewhat loosely therein, so that body member 38may be adjusted with respect to inner end member 37 to provide the smallrunning clearance described.

By suitably varying the setting of the screws 44 and pilot screws 48 theposition of the rotor 17 in the cavity 27 and the clearance thereof withrespect to the land 33 can properly be made.

The rotor 17 may be taper bored as seen in FIG. 1 to provide a pair oftapered bores such as shown at 53 and 54 with the larger diameters atthe ends of the rotor, the smaller inner ends of the bores 53 and 54intersecting along a common land 55. In lieu of taper boring, it ispreferred that the bore be of a constant diameter such as shown at 56separated by a land of smaller diameter at the key 20.

Irrespective of manner of forming the bore or bores in rotor 17, and thecontour of any land or surface of revolution therebetween they aredesigned to enable rotor 17 to have a maximum of wobble movement butnonetheless to run with a minimum clearance between the faces 34 and 36to obtain a maximum performance.

Such clearance between the faces 34 and 36 is maintained Without theneed for shims or other adjusting means. The longitudinal dimension ofbody member 28, for example, is accordingly made .001 to .002" greaterthan the longitudinal dimension of rotor 17, so that when outer endmember 38 is held to body member 28 by the screws 39 tapped into innerend member 37 the proper end clearances for the rotor will bemaintained. The rotor 17 can thus float endwise of itself independent ofmotor shaft irregularities. In such movement of rotor 17, it is notnecessary to lock the rotor and its driving shaft together to maintainthe proper end clearances.

It should be noted that the plastic key acts as an overload relief. Thatis, if a portion of the floating rotor does bind somehow with the bodythen the keys 19, 20 would shear before extensive damage could occur toeither the driven or the driving machines. Here again, the portions ofthe broken keys would lubricate rather than damage the rotating parts.

From the description foregoing it is believed evident that new anduseful improvements in rotating vane machines have been provided by thestructure used for mounting the same on a prime mover.

More specifically, the unique self-sizing dry lubricant keys assure:precise and leak tight fit of the key to motor shaft, free lateralmovement for centering and easy removal of the rotor, sound dampening,wear prevention and controlled overload shear action.

Having thus described this invention in such full, clear, concise andexact terms as to enable any person skilled in the art to which itpertains to make and use the same, and having set forth the best modecontemplated of carrying out this invention, the subject matter regardedas being patentable is particularly pointed out and distinctly claimedin what is claimed, it being understood that equivalents ormodifications of, or substitutions for, parts of the above specificallydescribed embodiment may be made Without departing from the scope of theinvention as set forth in what is claimed.

I claim:

1. The improvements in the combination of a prime mover and a pumpdriven thereby and mounted thereon, Where said prime mover has aprotruding shaft support with a driving shaft protruding from saidprotruding shaft support, an inner end member for said pump adapted tobe adjustably mounted on said protruding shaft support with saidprotruding shaft extending therethrough, a plurality of radially mountedthreaded adjusting means held in said inner end [member and adapted tobear against said bearing support for adjustment of the position of saidinner end member, a pump rotor mounted on that portion of the drivingshaft extending beyond said inner body member and turning therewith, anon-metallic key connecting said shaft to said rotor, said rotor havinga bore therein of larger diameter than the diameter of said drivingshaft, a central body member having a cavity therein for said rotor, aplurality of bores in said central body member extending parallel to theaxis of said driving shaft, screws of smaller diameter than said =boresfor holding said central body member to said inner end member andproviding for adjustment of said central body member with respect tosaid inner end member in directions transverse to the axis of rotationof said rotor to provide proper clearance of said rotor with respect toa land in the wall of said cavity and an outer end member adapted to besecured to said inner body member.

5 2. The combination of claim 1 wherein said non- 2,759,423 metallic keyis fabricated of plastic. 2,764,100 3. The combination of claim 2wherein said plastic key 2,833,465 comprises a dry lubricant hightemperature material. 3,282,222

4. The combination of claim 2 wherein said key is fabricated fromTeflon. 5

References Cited UNITED STATES PATENTS Keel 103118 Maisch 103118 CableZ30-139 Raufeisen et al 103118 DONLEY I. STOCKING, Primary Examiner.

WILBUR J. GOODLIN, Assistant Examiner.

US. Cl. X.R.

